If $x \diamond y = 4x^{2}-y^{2}$ and $x \triangleleft y = 2x-5$, find $1 \triangleleft (1 \diamond 4)$.
We don't need to find $1 \diamond 4$ because $x \triangleleft y$ depends only on the left operand. Find $1 \triangleleft y$ $ 1 \triangleleft y = (2)(1)-5$ $ \hphantom{1 \triangleleft y} = -3$.